The First Hundred Years' War (French: Première Guerre de Cent Ans; 1159–1259) was a series of conflicts and disputes during the High Middle Ages in which the House of Capet, rulers of the Kingdom of France, fought the House of Plantagenet (also known as the House of Anjou or the Angevins), rulers of the Kingdom of England. The conflict emerged over the fiefs in France held by the Angevins, which at their peak covered around half of the territory of the French realm. The struggle between the two dynasties resulted in the gradual conquest of these fiefs by the Capetians and their annexation to the French crown lands, as well as subsequent attempts by the House of Plantagenet to retake what they believed to be their rightful ancestral claims in western France.
While not a widely used term, "First Hundred Years’ War" is the designation most often applied to this period, referring retrospectively to the Anglo-French conflicts preceding the more widely recognized Hundred Years' War (1337–1453). These conflicts are often seen as a precursor to the latter, involving many of the same belligerents and dynasties. Like the Hundred Years' War, this conflict was not a single war, but rather a historiographical periodisation to encompass dynastic conflicts centered around the dispute over the Angevin Empire.
Overview
Origins
During the conflict, the continental possessions of the Kings of England were considered more important than their insular ones, covering a significantly greater area than the territories controlled directly by the Kings of France, who nonetheless remained the overlords of the former with regard to those continental lands. While the Capetian kings’ nominal suzerainty extended far beyond their small domain of Île-de-France, their actual power over many vassals, especially the Plantagenets, was limited. Both dynasties sought to strengthen their positions, not only through territorial consolidation but also through occasional claims to royal titles: Henry II initially hoped to secure the French throne for his son Henry the Young King before the birth of Philip Augustus, and a generation later Philip’s own son, Louis VIII, would assert a claim to the English crown during the First Barons’ War. These ambitions, combined with the Plantagenets’ control of the sovereign kingdom of England, intensified the rivalry and helped define the underlying causes of the conflict.
Time frame
Although the time frame of the conflict is generally accepted to be from the beginning of the '40 years war' in 1159 to the 1259 Treaty of Paris, a few preliminary and residual instances of conflict had occurred between the two dynasties such as the Capetian invasion of Plantagenet-held Duchy of Aquitaine in 1152, or during the Gascon War starting in 1294, which were both initiated for mostly the same underlying reasons as are seen for the rest of the conflict. They are, however, both relatively minor, and the latter conflict is sufficiently distant in time to be considered separate from the overall conflict. It is also reasonable to extend the start of the conflict to 1154, when the formation of the Angevin Empire can be seen as the true root of the conflict, rather than the dispute over Toulouse, which merely served as the justification for military action. The Hundred Year's War from 1337 to 1453 is also not accepted as part of the same conflict due to the differing casus belli used to initiate the war, and the fact that the two families involved were cadet branches of the Capetian, and eventually, Plantagenet dynasties (Valois and Lancastrian respectively).
The conflict can generally be divided into three distinct phases. The first phase saw the Angevin Empire maintaining dominance over their Capetian rivals. In the second phase, the Angevin Empire experienced a sudden collapse at the hands of the Capetians, culminating in a Capetian invasion of England. The third phase occurred with the Capetian kings now dominant on the continent, while the Plantagenets sought to reclaim the Angevin Empire through various means. It also included residual, more localised conflicts along the borderlands of the Plantagenets’ remaining continental possessions.
Warfare
The conflict occurred during a period when the majority of warfare was characterised by sieges, siege assaults, siege reliefs, raids, and skirmishes. This was largely due to two factors: the feudal structure of both kingdoms which hindered the formation of professional standing armies, and the defensive advantage provided by the widespread presence of castles. Consequently, warfare was more localised in nature and large pitched battles were relatively rare due to their typically decisive outcomes. This is best observed in the Vexin, where much of the early fighting took place, resulting in the construction of a dense network of castles on both sides, including the famous Château Gaillard. However, this did not lessen the brutality or the death toll. In fact, this style of conflict spread the burden of war across a broader spectrum of society, impacting people of various statuses.
While soldiers were often drawn from more distant regions, most combat involved the immediate stakeholders—local nobility and populace alike. As the Plantagenets lost territory on the continent, their ability to wage war became increasingly strained. They had to rely on hired mercenaries for deeper offensive campaigns into France. This is all in contrast to the later 'second' Hundred Years' War, during which the infantry revolution gained momentum, allowing for pitched battles to become more common, and the growing use of gunpowder began to undermine the strategic importance of castles.
Significance
The significance of the conflict is often viewed in the context of the later Hundred Years' War, which spanned from 1337 to 1453. Ironically, the intermarriages between the two dynasties—resulting from various peace settlements from the conflict—played a direct role in the Plantagenets' dynastic claim to the French throne, ultimately triggering the more famous Hundred Years' War. The French invasion of England in 1216 also played a significant role in the rise of English nationalism, reinforcing a collective identity that distinguished the English from their French adversaries. The enduring fear of another French invasion in the 14th century further galvanised the lower classes, prompting widespread military preparedness, particularly in the use of the longbow, as a means of defending the realm.
After the Plantagenet claims to western France ended with the Treaty of Paris in 1259, the English kings, in regards to their few remaining possessions on the continent, would remain vassals to the French kings and would become more English in nature. The Capetians were also able to consolidate their power, making the kingdom of France the wealthiest and most powerful state in medieval Western Europe.
Angevin ascendancy under Henry II: 1154–1189
In 1150, amidst a period of civil war in England over the succession of the crown known as the Anarchy, Henry II Plantagenet, a claimant to the throne by right of his mother Empress Matilda, received the Duchy of Normandy from his father Geoffrey V, Count of Anjou. In response to the looming threat of a united England, Normandy, and Anjou, Louis VII Capet of France put forward King Stephen of England's son, Eustace, as a pretender to the duchy of Normandy and launched a military campaign to remove Henry from the province. Peace was made in 1151 in which Henry accepted Louis as his feudal lord in response for recognition as the duke of Normandy.
When Geoffrey died in September 1151, Henry inherited the County of Anjou and Maine. On 18 May 1152 he became Duke of Aquitaine in right of his wife by marrying Eleanor of Aquitaine in Poitiers after her first marriage with Louis VII of France was annulled at the Council of Beaugency. As a result of this union, Henry had now possessed a larger proportion of France than Louis. Tensions between the two were revived. Louis organised a coalition against Henry including Stephen of England and Henry's younger brother Geoffrey, among a group of other nobles in France. Fighting broke out along the borders of Normandy, and Louis launched a campaign into Aquitaine. In England, Stephen laid siege to Wallingford Castle which was held by Henry's forces at the time. Henry responded by stabilising the Norman border, pillaging the Vexin and then striking south into Anjou against Geoffrey, capturing the castle of Montsoreau. Louis soon fell ill and withdrew the campaign, and Geoffrey was forced to come to terms with Henry.
On 6 November 1153, by the Treaty of Wallingford (or Treaty of Winchester), he was recognised as the successor of King Stephen of England. When the latter died on 25 October 1154, he ascended the throne of England under the name of Henry II. On Sunday 19 December he was crowned at Westminster Abbey. This marked the beginning of what is referred to by historians in the modern day as the Angevin Empire.
In 1156, Henry II expanded his power by seizing the Viscounty of Thouars, securing the vital communications route between his northern and southwestern lands. Two years later, in 1158, he annexed Nantes from the semi-independent Duchy of Brittany, tightening his grip on the region. The resources at the disposal of Henry now far exceeded those of the king of France. That same year, Henry sought to strengthen his family’s position in France by arranging a marriage between his eldest son, Henry the Young King, and Margaret of France, the daughter of Louis VII and his second wife, Constance of Castile. The match, confirmed in the Treaty of Gisors, included the Vexin, a strategically crucial frontier territory containing the castle of Gisors, as Margaret’s dowry. The agreement gave Henry direct control of the Vexin, to Louis’s alarm, and raised the prospect that the Young King might one day inherit the French throne, since Louis then lacked a male heir.
Outbreak of the Forty Years' War
In 1159, Henry claimed the County of Toulouse in right of his wife Eleanor of Aquitaine, descended from the earlier dukes of Aquitaine who had once controlled the county. The struggle over Toulouse soon brought the two monarchs into open confrontation. Henry gathered one of the largest armies of the age at Poitiers, drawing forces from England, Normandy, Anjou, Aquitaine, and Gascony, with reinforcements from Thierry of Flanders and King Malcolm IV of Scotland. His allies, the Trencavels and Ramon Berenguer IV of Barcelona, Count of Provence, pressed on Toulouse from the south, while Henry himself besieged the city. The siege ended abruptly when Louis VII entered Toulouse with a small escort to support his brother-in-law Raymond V, Count of Toulouse; Henry, unwilling to attack his feudal overlord directly, withdrew. Nonetheless, he seised Cahors and several castles in the Garonne valley in Quercy. The ensuing contest over Toulouse earned the label of the “forty years’ war” in later chronicles.
The dynastic balance shifted after Constance’s death in October 1160, when Louis married Adela of Champagne, thereby consolidating alliances with Theobald V of Blois and Odo II of Burgundy in 1160. Despite initial attempts to repair relations, diplomacy broke down. Henry seized the Vexin and forced a marriage between Young Henry and Margaret, angering Louis. Theobald V, Count of Blois, mobilised his forces on behalf of Louis, however, Henry responded with a surprise attack on Chaumont, capturing Theobald's castle after a successful siege. Henry mounted another campaign into Toulouse in 1161, but withdrew again, leaving the fighting to his allies, including Alfonso II of Aragon and the Archbishop of Bordeaux. Another peace was negotiated in the autumn of 1161, followed by a second peace treaty in 1162 overseen by Pope Alexander III.
The rivalry continued across France. In 1164, Henry seized lands along the Norman–Breton frontier, and in 1166 he invaded Brittany outright, forcing Duke Conan IV to abdicate and betrothing Conan's daughter Constance to his son Geoffrey, thereby securing the duchy for the Angevin dynasty. Meanwhile, Louis the gained the support of Philip, Count of Flanders, who feared the growth of Angevin power. In 1169, further negotiations took place at the Conference of Montmirail, where Henry attempted to formalise the division of his empire among his sons. At this meeting, his son Richard was betrothed to Louis’s daughter Alys, and Henry’s heirs performed homage to the French king for their projected continental inheritances. Though this seemed to affirm Louis’s overlordship, he used the situation to encourage rivalries among Henry’s sons, rather than to stabilise relations. In 1165 the birth of Adela’s son, the future Philip II Augustus, restored his confidence by ensuring the French crown would remain within the Capetian line